We know how Mozilla must feel. It spends every waking hour tweaking and perfecting Firefox to eek out as much performance as possible, only to see it all ruined by lousy add-ons that weigh the browser down like a block of cement. It's apparently now had enough, however, and has gone as far as to publish a list that exposes the worst offenders. As of this writing, the two biggest drags on the browser by far are the FoxLingo translator / dictionary and Firebug developer tool add-on which, according to Mozilla, each make the browser 74 percent slower to start up. That list is just part of a broader crackdown on poor performing add-ons. Mozilla says it's also instituting automa